Prep : 40 minutes + overnight Cook : 50 minutes Makes 4 half-pints
2 large thick-skinned grapefruits
1 large thick-skinned lemon
2 cups water
4 cups sugar
1. Peel grapefruit and lemon ; cut away inner white part leaving rind and white pith about 3/8-inch thick . Cut into shivers 3/4-inch long and 1/8-inch wide . Discard excess pith , fiber and seeds . Chop fruit coarsely , reserving juice .
2 . In an 8-quart nonreactive heavy kettle over moderately high heat , simmer rind , chopped fruit , reserved juice and water , uncovered for 10 minutes . Pour in a large heatproof glass bowl and let stand , covered in a cool place overnight .
3. Return mixture to kettle , add sugar and set over moderate heat . Insert a candy thermometer and bring to a boil , stirring until sugar dissolves . Continue boiling , stirring occasionally until thermometer registers 21*F to 220*F.
4 . Remove from the heat , skim off foam and ladle into sterilized half-pint canning jars , leaving 1/4-inch head space . Wipe rims and seal . Place label and store in a cool dark place .
Prepare as directed above , substituting 2 large navel oranges or Valencia oranges for the grapefruit . Do not discard seeds ; instead tie seeds in cheesecloth and simmer along with rind and chopped fruit . Remove bag of seeds before cooling overnight , then proceed as directed . Makes 4 half-pints.
Prepare as directed . substituting 6 large limes for the grapefruit or oranges and using 1-1/2 cups sugar to each 1 cup fruit mixture . Stir in 1/3 finely chopped crystallized ginger after sugar dissolves in step 3 , then proceed as directed . Makes 4 half-pints .